Packaging for free-flowing products, consisting of a heat-sealed bag

ABSTRACT

Packaging for free-flowing products consisting of a tubular bag composed of a flexible material. One end, which lies flat when the bag is filled, is formed by two broad-face panels lying flat against one another and narrow-face panels that are folded back by center fold lines between the opposite edges of the narrow-face panels, and positioned between the marginal areas of the broad-face panels. A side fold connects each narrow-face panel to one broad-face panel and another side fold connects the narrow-face panel to the other broad-face panel. The fold lines extend substantially parallel to the longitudinal axis of the bag. The end of the bag is closed by a sealing weld that extends in a transverse direction to the longitudinal axis of the bag. The sealing weld is controlled to be weaker than the other welds which connect the panels to form the panels into a bag for containing the product. Preferably the outer surfaces of the panels are treated to prevent their being sealed together when folded back

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a '365(c) continuation of PCT/EP2004/012281 filedOct. 29, 2004, which claims priority to DE Application 103 52 019.8,filed Nov. 7, 2003, each of the foregoing applications is incorporatedherein by reference.

FIELD OF THE INVENTION

The invention relates to a packaging for free-flowing productsconsisting of a tubular bag composed of a flexible material, and saidpackaging, when full, has an end that lies flat, formed by twobroad-face panels lying flat against one another and narrow-face panelsthat are folded inwards at both edges of said panels and lie between thelatter, wherein a side fold adjoins one broad-face panel and anotherside fold adjoins the other broad-face panel, the end of the bag beingclosed by means of a sealing weld that extends substantially in atransverse direction to the longitudinal axis of the bag.

BACKGROUND OF THE INVENTION

These types of packaging bags are used as e.g. a receptacle for powdereddetergents, and particularly as refill packaging, i.e. the customeropens the tubular bag and pours out the content, namely the detergent,into a long-term use bin. The empty bag can then be folded flat anddisposed of in a space saving way.

Known packaging of this type are sealed on the upper side with acontinuous upper welded seam that bonds both the broad-faced panel endsand the folded-in side fold ends of the narrow-faced panels to eachother. The outer regions of the upper weld are therefore each four-ply,whereas the upper weld is two-ply in their middle region, i.e. only thebroad-faced panels are bonded to one another. As a result, it ispractically impossible to open the packaging without a utensil. Withouta utensil the consumer is only able to pull it open in the middle regionbetween the side folds, where the weld is two-ply. Opening by pullingcauses ripping in the transition region between the two-ply and thefour-ply weld zones. These rips proceed uncontrollably strongly in thedirection of the bottom of the bag. Therefore, to be certain of beingable to empty out the contents, the refill packaging has to be openedwith a utensil, such as scissors. A label is therefore provided on thepackaging to advise the consumer to use scissors.

A packaging bag whose external sides are respectively sealed with asealing weld is known from WO 03/010067, the sealing weld being two-plyin the middle region and four-ply in both the outer regions. In orderthat such a bag can be opened as easily as possible without utensils, itis provided with a line of weakness, offset from the upper sealing weld,for example in the form of a perforation in the region of a broad-facepanel. However, such a line of weakness brings the inherent danger of anunwanted opening, for example during transport or product handling.

A packaging bag, known from EP 1 163 166 B1, is also sealed with a topsealing weld that is four-ply in the side regions and two-ply in themiddle region. To facilitate the opening of the bag, the sealing weld isarranged offset to the edge of the bag to form an engagement portion onthe edge side and designed convexly directed towards the inside.

Finally, a packaging bag is known from EP 0 343 629 A1 with a continuoustwo-ply sealing weld that is triangular in shape. The regions of filmsealed to one another are thus provided with a peelable coating intendedto facilitate opening without a utensil. However, this packaging bagdoes not have any folded sides.

SUMMARY OF THE INVENTION

The object of the invention is to enable a controlled opening of thisfamily of package, without opening utensils.

According to the invention, this object is achieved for a package of thetype described in the introduction by providing the sealing weld in theregion of the side folds only between the respective side fold and theneighboring broad-face panel.

Different from the family of packages of this type, the package inaccordance with the application therefore has no four-ply sealing weldregion in the region of the end of the bag, as the folded side folds arenot sealed to each other, but rather only to the neighboring broad-facepanel. In this way a problem-free opening of the package ispossible—also without utensils—without the danger of uncontrolledripping.

In order to reliably prevent the respective side folds to be sealed whenthe package is being sealed, the narrow-face panels in the region of theside folds lying against each other are each provided with ananti-adhesion coating.

In order to further facilitate the opening, the inner side of thetubular bag, at least in the region of the sealing weld, is designed inthe known manner to have a peelable surface. To facilitate themanufacture, preferably all the inner side of the tubular bag has apeelable surface.

The tubular bag consists quite particularly preferably of a coextrudedcomposite film of OPP and PE. Quite preferably, the peelable surface isrealized such that it is formed from a sealing layer of PE with amodified blend, such as polybutene.

In order to facilitate the opening process and to offer the consumer asufficiently large region to use his hands, the sealing weld is offsetfrom the edge of the bag end.

In order to improve transport and storage and to ensure a good dropstrength, such that, for example, the sealing weld does not burst afterthe package falls from a shelf, the end of the bag is preferably turnedback and attached to the external face of the bag. The attachment can becarried out, for example, by the use of hot air. Turning over the end ofthe bag prevents the force generated by the fall from directly strikingthe sealing weld. The generated forces are directed much more to theturned back bag end, preventing damage to the sealing weld.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention is described in more detail below, exemplified by thedrawing. This shows in:

FIG. 1 is a perspective illustration a package with a sealing weld;

FIG. 2 a side view of the package shown in FIG. 1;

FIG. 3 shows the package with the sealed bag end turned back;

FIG. 4 shows the closed package before opening;

FIG. 5 shows the opening process; and

FIG. 6 a magnified fragmentary cross sectional view of the constructionof the layers of two regions of film lying against one another in thetubular bag of the package.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

A packaging for free-flowing products, for example powdered detergent,is shown in FIG. 1 denoted in general by 1. This packaging consists of atubular bag 2 that is closed at the bottom with a bottom seal (notshown). The bag may be formed with front, back and side panels which aretubulated by at least one lengthwise seam (not shown) extendingsubstantially parallel to the longitudinal axis of the bag. At the top,the tubular bag 2 is first opened and is filled with powdered productonly up to the point that, when full, a bag end 3 remains flat. This bagtop end 3 is formed from two broad-face panels 4 and 5 lying flatagainst one another and two narrow-face panels, one of which is shown at9, that are folded inwards at both edges of said panels and lie betweenthe broad-face panels 4, and 5, wherein a side fold line 6 joins onebroad-face panel 4 with the panel 9, and the other side fold line 7joins the other broad-face panel 5 with the panel 9. The panel 9 isfolded back upon itself at a fold line 19 (FIG. 2) centrally between thebroad-face panels 4 and 5.

The filled bag 2 or the flat-lying bag end 3 is sealed by means of asealing weld 8 that extends substantially in a transverse direction tothe longitudinal axis of the bag. Basic to the invention is that thesealing weld 8 in the region of the side folds 6,7 is only providedbetween the respective side folds 6 or 7 and the neighboring broad-facepanel 4 or 5, i.e. as can best be seen in FIG. 1, the folded-backsections of the panel 9 between of the side folds lines 6,7 are notbonded to each other by a sealing weld. In this manner the total regionof the sealing weld 8 is only two-ply; four-ply regions do not exist.

In order to prevent an unwanted sealing of the neighboring side folds6,7, an anti-adhesion coating is provided at least in the region wherethe side folds 6,7 adjoin each other; to simplify the manufacture, thecomplete external side of the tubular bag can be provided with ananti-adhesion coating. The inner side 2 of the tubular bag, at least inthe region of the sealing weld 8, has a peelable surface; also here, tosimplify the manufacture, it is preferred that the complete inner sideof the tubular bag 2 has a peelable surface. Thus, the tubular bag 2preferably consists of a coextruded composite film of OPP and PE, as canbe best discerned from FIG. 6, in which two regions of the broad-facepanels 4,5, lying against one another, are illustrated in the region ofthe bag end 3. The coextruded composite film consists of OPP and PE;from inside to outside preferably of an inner PE layer with a modifiedblend, such as polybutene, this region is indicated with the referencenumber 10. Two coextruded polyethylene layers 11 are juxtaposed and aprinting 12 is respectively provided on the external sides. Thisprinting 12 receives an OPP layer 13 that is finally provided on theexterior with an anti-adhesion coating 14.

The closed packaging is illustrated in FIG. 4, wherein it can be seenthat the regions of the side folds 6, 7 are not sealed to one another.It can also be seen that the sealing weld 8 is offset from the edge,such that in the edge region two flaps 15 remain that can be grasped bythe consumer. Preferably, the end of the bag 3 is turned back andfastened to the external side of the bag 2, as is seen in FIG. 3. Thisfastening can be made, for example, with hot air and ensures that thepackage has an adequate drop resistance, i.e. if the package falls froma shelf, for example, then practically no forces act on the sealing weld8.

To open the package 1 from its transport and sales configuration, thenaccording to FIG. 3 the end of the bag 3 is detached from the exteriorof the bag and returned to the configuration illustrated in FIG. 4. Theconsumer then grasps both regions 15 with both hands, as shown in FIG.5, and pulls both ends apart, such that the bag 2 can be extremelyeasily opened along the sealing weld 8 and along the peelable surfaceslying against each other, without the need for a utensil.

The previously described peelable layer of film is manufactured in sucha way that a polyisobutylene additive is blended in a ratio of 10 to 15%with the PE pellets used for the blown film extrusion for the inner filmlayer 11. In this way the whole of the inner surface is renderedpeelable and on pulling apart/separating the films, there occurs acohesive fracture, i.e. both the films sealed together are practicallyself-separating.

The sealing weld 8 is preferably prepared by means of special sealingjaws that have a smooth jaw geometry. The sealing temperature ispreferably controlled within a very exact temperature window (tolerance3° C.), quite preferable sealing temperatures have been found to be upto 140° C. and allow an opening of the sealing weld with opening forcesof ca. 5 N/15 mm. On increasing the sealing weld temperature to above150° C., however, the sealing weld strength increases strongly to valuesof around 35 N/15 mm. This value is one that practically can no longerbe opened by hand and coincidentally this temperature range is suitablefor making the lengthwise and bottom welds of the packaging bag 2 whichare not visible in the illustrations of the bag shown in FIGS. 1-5.

1. Packaging for free-flowing products consisting of a tubular bagcomposed of a flexible material, and said packaging, when full, havingone end, formed by two broad-face panels lying flat against one anotherand two narrow-face panels that are connected between said broad-facepanels by fold lines, said narrow-face panels having sections which arefolded back upon each other and confront said broad-face panels,wherein, respectively, one of said fold lines joins one broad-face panelwith said narrow-face panel, and another of said side fold lines joinsthe other broad-face panel with said narrow-face panel, and at least onesealing weld that extends substantially in a transverse direction to thelongitudinal axis of the bag along the top of the two broad faced panelsand the narrow-face panels between them, to close the end of the bag,wherein said at least one sealing weld between said side fold lineseffecting a seal only between the sections of the narrow-face panels andthe confronting broad-face panel without a seal between the folded-backsections of said narrow-face panels.
 2. Packaging according to claim 1,wherein the folded-back sections of the narrow-face panels between saidside fold lines and lying against one another are each provided with ananti-adhesive coating.
 3. Packaging according to claim 1, wherein saidtubular bag has an inner side with peelable surface, at least in theregion of the sealing weld.
 4. Packaging according to claim 1, whereinsaid tubular bag consists of a coextruded composite film of OPP and PE.5. Packaging according to claim 3, wherein the peelable surface isformed from a sealing layer of PE with a modified blend of polybutene.6. Packaging according to claim 1, wherein said panels have a free edgeacross said one end, said sealing weld being offset from said free edge.7. Packaging according to claim 1, wherein said one end of the bag isturned back and attached to an outer side of the bag.
 8. Packagingaccording to claim 1, wherein said bag has lengthwise and bottom weldsconnecting said panels to form a closed receptacle for the products,said sealing weld a providing a greater facility for being opened thansaid lengthwise and bottom welds.